Marie's Doll

Conditional: during the Research Facility escape, at the foot of the Collection & Testing East stairs, just before Grace breaks into a panicked run. It only spawns if in this run you: 1) waited a full 15 minutes in Processing (ch05) before draining the water; 2) got through the conveyor without landing a killing blow yourself (hit their knees and push them into the grinder's teeth); 3) after the Basement, flushed the toilet in the Restroom by the Kitchen 8 times before heading out to the Courtyard.

The key to the Final Puzzle (hidden challenge, 20,000 CP). Carry the doll and Emily to the Lead Researcher's Office puzzle cabinet and enter the 12-symbol code.

Put it in the Item Box: in a new game it shows up in Grace's Item Box. In that run, get the ID Wristband (Level 3), open Emily's cell and carry her to the cabinet with the doll. Counting 115 bodies dropping into the pit (about 8.5 minutes) doesn't work. If it doesn't appear, reload from before draining Processing. Description: "We'll be together forever and ever." The community worked the conditions out; not every source has tested them. It is easier on Casual.